Not Applicable.
Not Applicable.
1. Field of the Invention
The present invention relates to fluid handling devices, and in particular, to fluid handling devices employing a plurality of stacked plates for dispersal, separation and turbulent mixing of fluids.
2. Brief Description of the Related Art
There are numerous applications requiring the continuous mixing of two or more fluids. Example includes foams, paints, solvents, and components of chemical processes. Such fluids may have varying degrees of viscosity and miscibility which can render thorough mixing difficult to achieve on a continuous basis. Information relevant to attempts to address this problem can be found in the following U.S. patents. These references mentioned in this background section are not admitted to be prior art with respect to the present invention.
A typical example of an in-line mixing device is disclosed in U.S. Pat. No. 3,941,355 to Simpson. Simpson discloses a device for mixing foam ingredients. A series of longitudinally spaced discs are disposed on a shaft within a cylindrical bore. The discs have radial slots on alternating sides of the discs so that the fluids are forced to take a path which flows through the alternating slots and divides and flows around the shaft in the space between the discs. U.S. Pat. No. 3,363,412 to Cole discloses a similar pattern of alternating cutouts on the sides of a plurality of stacked discs. However, Cole does not have the central shaft of Simpson.
U.S. Pat. No. 5,547,281 to Brooks discloses a mixing apparatus having first and second end walls and an intermediate wall disposed between the end walls in a tubular member. The end walls have at least one aperture and the intermediate wall is spaced from the interior of the tubular member to form an annular passage. The fluids to be mixed therefore flow through the apertures in the first end wall, through the annular passage around the intermediate wall, and then exit through the aperture in the second end wall.
U.S. Pat. No. 5,232,283 to Goebel et al. discloses a mixing apparatus comprising a tray with an aperture in the middle. A cap with opposed openings covers the aperture. Fluids pass through the opening into a pan below the tray. A tube encircling the aperture below the cap has notches to allow the fluids to enter the pan. Radially spaced risers extending from the bottom of the pan have upper ends above the notches and below the tray. The risers have openings through which the fluids pass.
U.S. Pat. No. 4,441,823 to Power discloses a liquid mixer with a plurality of slotted plates spaced apart within a chamber. The slots are angled to the exit face of the plate so as to induce turbulence. The slots are preferably radially disposed in the circular plates.
U.S. Pat. No. 5,863,129 to Smith discloses a mixing device comprising stacks of three different types of cylindrical mixing elements. Each of the mixing elements has a pair of inlets, a central chamber and an outlet.
U.S. Pat. No. 5,997,283 to Spiros discloses an electrolysis system in which a stack of plates have a polygonal shape and have projections by which the plates are spaced apart.
Each of these references suffers from the disadvantage of not inducing sufficient turbulence and intermingling of the fluids to thoroughly mix fluids of varying viscosity and miscibility. Further, fluid separation may also be accomplished more efficiently by devices having enhanced resistance to fluid motion, which may be developed by structures related to the same type of structures that enhance turbulence.
The limitations of the prior art are overcome by the present invention as described below.
The present invention is directed to a device that satisfies the needs identified above. The invention is a fluid handling device to assist in the mixing or separation of two or more fluids. Depending on the application, structures in the device enhance turbulence in moving fluids or provide resistance to fluid motion. In the first case mixing is enhanced; in the second, separation is enhanced.
The device utilizes a stack of plates. Two types of plates are alternated to achieve the mixing or separation effect. One type of plate has peripheral spaces around which the fluids may flow; the other type of plate has at least one aperture, which may be centrally located. Both types of plates are provided with a plurality of projections that serve to space the plates apart and to provide additional turbulent mixing or enhanced fluid resistance of the fluids as they flow around the projections. When being mixed, the fluids are forced to proceed back and forth through the alternating plates until thoroughly mixed.
The device may also be employed for separation of fluid components based on varying density of the fluid components. The preferred embodiment for fluid separation mounts the plates for rotation within a housing so that the separation effect occurs by centrifugal effects enhanced by the resistance to fluid motion provided by the plates and projections within the device.
In a preferred embodiment of the present invention directed to mixing of two or more fluids, the fluids may be introduced through a plate with at least one aperture, then forced around the periphery of the next plate and so forth. When mixing two or more fluids, the fluid flow is alternately divided and recombined for thorough mixing.
While the plates may be adapted for use in a cylindrical housing, the invention is not so limited. The plates may, for example, be designed to fit within a housing of polygonal cross-section. In such a case, the second type of plate having the central aperture may have the same polygonal cross-section. The first type of plate is then shaped so that the extreme points on the periphery fit against the walls of the housing while the peripheral segments between these extreme points are withdrawn from the walls of the housing so as to provide gaps around which the fluids may flow.
The projections may be tapered and circular in cross-section. Other shapes, both tapered and non-tapered, are contemplated as being within the scope of the invention. The projections, may for example, be square, or more generally, polygonal in cross-section. More angular shapes may assist in turbulent mixing or provide enhanced fluid resistance. These more angular shapes may be desirable depending on the viscosity of the fluids. Various numbers and arrangements of the projections are contemplated as being within the scope of the invention. Further the heights of the projections may vary depending upon the application. For example, depending on the viscosity of the fluids being handled, it is desirable to adjust the separation between adjacent pairs of plates to obtain the appropriate degree of turbulence for optimum mixing or fluid separation. The mixing effect may be enhanced by placing a plurality of spheres between the projections. The spheres are sized to have a diameter less than the height between the plates and less than the distance separating the projections so that the spheres are able to tumble in the fluids. The tumbling action not only enhances mixing but also may be useful in grinding and dispersing solid particles in the fluids.
The device is intended to be applicable to the mixing or separation of a plurality of fluids. The fluids may be introduced into the housing containing the stack of plates at various points as required by the particular fluids being mixed. For example, two fluids to be mixed may advantageously be introduced at one end of the housing and the two fluids will be mixed together through the entire series of plates. Alternatively, one or more fluids may be introduced into, or removed from, the housing at points along the fluid path after one or more fluids have been introduced into the first end of the housing.
The device may be mounted both horizontally or vertically with respect to the major axis of the device. The plates may be interlocked and mounted for rotation within the housing for separation or mixing of fluids. The device may be employed for both mixing and separation operations simultaneously. For example, two liquids, at least one of which contains a gaseous component, could be introduced at one end of the device. As the two liquids are mixed, the gaseous component, from the effect of gravity alone or as enhanced by centrifugal effects, would tend to separate from the mixed liquids and could therefore be drawn off at some intermediate point from the device.
The description above has used the term xe2x80x9cfluidxe2x80x9d to mean both liquids and gases, including liquids and gases carrying entrained and suspended solids. The plates may be constructed of any suitable material for the type of fluids being mixed.
It is therefore an object of the present invention to provide for device to assist in the mixing or separation or two or more fluids in which a stack of two types of plates are alternated to achieve a fluid resistance effect.
It is a further object of the present invention to provide for such a fluid handling device is which one type of plate has peripheral spaces around which the fluids may flow and the other type of plate has at least one aperture which may be centrally located.
It is also an object of the present invention to provide such a fluid handling device in which the plates are spaced apart by pluralities of projections which assist in the turbulent mixing or separation of the fluids.
It is a still further object of the present invention to provide such a fluid handling device in which the stacked plates are interlocked together and mounted for rotation within a housing.
These and other features, objects and advantages of the present invention will become better understood from a consideration of the following detailed description of the preferred embodiments and appended claims in conjunction with the drawings as described following: